Good afternoon.
In the Checkbox connection settings, it is possible to enable logging of requests, after which the
https://kiyservice.1b.app/admin/logs/showall/ajax/?file=checkbox-2023-07-31.log file will contain information about them.
In your example, you can see that the amount for the positions will be 592, and you transfer the payment to 593 - that's the change.
I assume that you have some kind of rounding set up when transferring, that the prices of products are transferred rounded down to integers, which is why the difference is obtained.